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<pre><span class="sourceLineNo">001</span><a name="line.1"></a>
<span class="sourceLineNo">002</span>/*<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Copyright (C) 2011 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<span class="sourceLineNo">004</span> *<a name="line.4"></a>
<span class="sourceLineNo">005</span> * $Id: CSVOutput.html 740 2013-10-02 21:27:31Z archie.cobbs $<a name="line.5"></a>
<span class="sourceLineNo">006</span> */<a name="line.6"></a>
<span class="sourceLineNo">007</span><a name="line.7"></a>
<span class="sourceLineNo">008</span>package org.dellroad.stuff.io;<a name="line.8"></a>
<span class="sourceLineNo">009</span><a name="line.9"></a>
<span class="sourceLineNo">010</span>import au.com.bytecode.opencsv.CSVWriter;<a name="line.10"></a>
<span class="sourceLineNo">011</span><a name="line.11"></a>
<span class="sourceLineNo">012</span>import java.io.BufferedWriter;<a name="line.12"></a>
<span class="sourceLineNo">013</span>import java.io.IOException;<a name="line.13"></a>
<span class="sourceLineNo">014</span>import java.io.Writer;<a name="line.14"></a>
<span class="sourceLineNo">015</span>import java.util.Arrays;<a name="line.15"></a>
<span class="sourceLineNo">016</span>import java.util.Date;<a name="line.16"></a>
<span class="sourceLineNo">017</span>import java.util.HashSet;<a name="line.17"></a>
<span class="sourceLineNo">018</span>import java.util.LinkedHashSet;<a name="line.18"></a>
<span class="sourceLineNo">019</span>import java.util.Map;<a name="line.19"></a>
<span class="sourceLineNo">020</span><a name="line.20"></a>
<span class="sourceLineNo">021</span>import org.dellroad.stuff.string.DateEncoder;<a name="line.21"></a>
<span class="sourceLineNo">022</span><a name="line.22"></a>
<span class="sourceLineNo">023</span>/**<a name="line.23"></a>
<span class="sourceLineNo">024</span> * CSV file output stream that ensures values are matched to the correct columns.<a name="line.24"></a>
<span class="sourceLineNo">025</span> * This class requires the &lt;a href="http://opencsv.sourceforge.net/"&gt;OpenCSV&lt;/a&gt; library.<a name="line.25"></a>
<span class="sourceLineNo">026</span> *<a name="line.26"></a>
<span class="sourceLineNo">027</span> * @see &lt;a href="http://opencsv.sourceforge.net/"&gt;OpenCSV&lt;/a&gt;<a name="line.27"></a>
<span class="sourceLineNo">028</span> */<a name="line.28"></a>
<span class="sourceLineNo">029</span>public class CSVOutput {<a name="line.29"></a>
<span class="sourceLineNo">030</span><a name="line.30"></a>
<span class="sourceLineNo">031</span>    private final CSVWriter writer;<a name="line.31"></a>
<span class="sourceLineNo">032</span>    private final String[] columns;<a name="line.32"></a>
<span class="sourceLineNo">033</span><a name="line.33"></a>
<span class="sourceLineNo">034</span>    /**<a name="line.34"></a>
<span class="sourceLineNo">035</span>     * Constructor.<a name="line.35"></a>
<span class="sourceLineNo">036</span>     *<a name="line.36"></a>
<span class="sourceLineNo">037</span>     * &lt;p&gt;<a name="line.37"></a>
<span class="sourceLineNo">038</span>     * The column headers will be written out automatically.<a name="line.38"></a>
<span class="sourceLineNo">039</span>     * &lt;/p&gt;<a name="line.39"></a>
<span class="sourceLineNo">040</span>     *<a name="line.40"></a>
<span class="sourceLineNo">041</span>     * @param writer destination for the CSV output<a name="line.41"></a>
<span class="sourceLineNo">042</span>     * @param columns CSV columns names in their desired order<a name="line.42"></a>
<span class="sourceLineNo">043</span>     * @throws IllegalArgumentException if {@code writer} is null<a name="line.43"></a>
<span class="sourceLineNo">044</span>     * @throws IllegalArgumentException if {@code columns} is null<a name="line.44"></a>
<span class="sourceLineNo">045</span>     * @throws IllegalArgumentException if {@code columns} contains a duplicate column name<a name="line.45"></a>
<span class="sourceLineNo">046</span>     */<a name="line.46"></a>
<span class="sourceLineNo">047</span>    public CSVOutput(Writer writer, String... columns) {<a name="line.47"></a>
<span class="sourceLineNo">048</span>        this(writer, Arrays.asList(columns));<a name="line.48"></a>
<span class="sourceLineNo">049</span>    }<a name="line.49"></a>
<span class="sourceLineNo">050</span><a name="line.50"></a>
<span class="sourceLineNo">051</span>    /**<a name="line.51"></a>
<span class="sourceLineNo">052</span>     * Constructor.<a name="line.52"></a>
<span class="sourceLineNo">053</span>     *<a name="line.53"></a>
<span class="sourceLineNo">054</span>     * &lt;p&gt;<a name="line.54"></a>
<span class="sourceLineNo">055</span>     * The column headers will be written out automatically.<a name="line.55"></a>
<span class="sourceLineNo">056</span>     * &lt;/p&gt;<a name="line.56"></a>
<span class="sourceLineNo">057</span>     *<a name="line.57"></a>
<span class="sourceLineNo">058</span>     * @param writer destination for the CSV output<a name="line.58"></a>
<span class="sourceLineNo">059</span>     * @param columns CSV columns names, iterated in their desired order<a name="line.59"></a>
<span class="sourceLineNo">060</span>     * @throws IllegalArgumentException if {@code writer} is null<a name="line.60"></a>
<span class="sourceLineNo">061</span>     * @throws IllegalArgumentException if {@code columns} is null<a name="line.61"></a>
<span class="sourceLineNo">062</span>     * @throws IllegalArgumentException if {@code columns} contains a duplicate column name<a name="line.62"></a>
<span class="sourceLineNo">063</span>     */<a name="line.63"></a>
<span class="sourceLineNo">064</span>    public CSVOutput(Writer writer, Iterable&lt;String&gt; columns) {<a name="line.64"></a>
<span class="sourceLineNo">065</span>        this(new CSVWriter(new BufferedWriter(writer)), columns);<a name="line.65"></a>
<span class="sourceLineNo">066</span>        if (writer == null)<a name="line.66"></a>
<span class="sourceLineNo">067</span>            throw new IllegalArgumentException("null writer");<a name="line.67"></a>
<span class="sourceLineNo">068</span>    }<a name="line.68"></a>
<span class="sourceLineNo">069</span><a name="line.69"></a>
<span class="sourceLineNo">070</span>    /**<a name="line.70"></a>
<span class="sourceLineNo">071</span>     * Constructor.<a name="line.71"></a>
<span class="sourceLineNo">072</span>     *<a name="line.72"></a>
<span class="sourceLineNo">073</span>     * &lt;p&gt;<a name="line.73"></a>
<span class="sourceLineNo">074</span>     * The column headers will be written out automatically.<a name="line.74"></a>
<span class="sourceLineNo">075</span>     * &lt;/p&gt;<a name="line.75"></a>
<span class="sourceLineNo">076</span>     *<a name="line.76"></a>
<span class="sourceLineNo">077</span>     * @param writer CSV output object<a name="line.77"></a>
<span class="sourceLineNo">078</span>     * @param columns CSV columns names, iterated in their desired order<a name="line.78"></a>
<span class="sourceLineNo">079</span>     * @throws IllegalArgumentException if {@code writer} is null<a name="line.79"></a>
<span class="sourceLineNo">080</span>     * @throws IllegalArgumentException if {@code columns} is null<a name="line.80"></a>
<span class="sourceLineNo">081</span>     * @throws IllegalArgumentException if {@code columns} contains a duplicate column name<a name="line.81"></a>
<span class="sourceLineNo">082</span>     */<a name="line.82"></a>
<span class="sourceLineNo">083</span>    public CSVOutput(CSVWriter writer, Iterable&lt;String&gt; columns) {<a name="line.83"></a>
<span class="sourceLineNo">084</span>        if (writer == null)<a name="line.84"></a>
<span class="sourceLineNo">085</span>            throw new IllegalArgumentException("null writer");<a name="line.85"></a>
<span class="sourceLineNo">086</span>        if (columns == null)<a name="line.86"></a>
<span class="sourceLineNo">087</span>            throw new IllegalArgumentException("null columns");<a name="line.87"></a>
<span class="sourceLineNo">088</span>        this.writer = writer;<a name="line.88"></a>
<span class="sourceLineNo">089</span>        LinkedHashSet&lt;String&gt; columnSet = new LinkedHashSet&lt;String&gt;();<a name="line.89"></a>
<span class="sourceLineNo">090</span>        for (String column : columns) {<a name="line.90"></a>
<span class="sourceLineNo">091</span>            if (!columnSet.add(column))<a name="line.91"></a>
<span class="sourceLineNo">092</span>                throw new IllegalArgumentException("duplicate column name `" + column + "'");<a name="line.92"></a>
<span class="sourceLineNo">093</span>        }<a name="line.93"></a>
<span class="sourceLineNo">094</span>        this.columns = columnSet.toArray(new String[columnSet.size()]);<a name="line.94"></a>
<span class="sourceLineNo">095</span><a name="line.95"></a>
<span class="sourceLineNo">096</span>        // Output header<a name="line.96"></a>
<span class="sourceLineNo">097</span>        this.writer.writeNext(this.columns);<a name="line.97"></a>
<span class="sourceLineNo">098</span>    }<a name="line.98"></a>
<span class="sourceLineNo">099</span><a name="line.99"></a>
<span class="sourceLineNo">100</span>    /**<a name="line.100"></a>
<span class="sourceLineNo">101</span>     * Output a CSV row.<a name="line.101"></a>
<span class="sourceLineNo">102</span>     *<a name="line.102"></a>
<span class="sourceLineNo">103</span>     * @param row mapping from column name to value; missing or values are treated as null<a name="line.103"></a>
<span class="sourceLineNo">104</span>     * @throws IllegalArgumentException if {@code row} contains an unknown column name<a name="line.104"></a>
<span class="sourceLineNo">105</span>     */<a name="line.105"></a>
<span class="sourceLineNo">106</span>    public void writeRow(Map&lt;String, ?&gt; row) {<a name="line.106"></a>
<span class="sourceLineNo">107</span><a name="line.107"></a>
<span class="sourceLineNo">108</span>        // Sanity check column names<a name="line.108"></a>
<span class="sourceLineNo">109</span>        HashSet&lt;String&gt; unknowns = new HashSet&lt;String&gt;(row.keySet());<a name="line.109"></a>
<span class="sourceLineNo">110</span>        unknowns.removeAll(Arrays.asList(this.columns));<a name="line.110"></a>
<span class="sourceLineNo">111</span>        if (!unknowns.isEmpty())<a name="line.111"></a>
<span class="sourceLineNo">112</span>            throw new IllegalArgumentException("row contains unknown column(s): " + unknowns);<a name="line.112"></a>
<span class="sourceLineNo">113</span><a name="line.113"></a>
<span class="sourceLineNo">114</span>        // Format columns<a name="line.114"></a>
<span class="sourceLineNo">115</span>        String[] values = new String[this.columns.length];<a name="line.115"></a>
<span class="sourceLineNo">116</span>        for (int i = 0; i &lt; this.columns.length; i++)<a name="line.116"></a>
<span class="sourceLineNo">117</span>            values[i] = this.formatObject(this.columns[i], row.get(this.columns[i]));<a name="line.117"></a>
<span class="sourceLineNo">118</span><a name="line.118"></a>
<span class="sourceLineNo">119</span>        // Output row<a name="line.119"></a>
<span class="sourceLineNo">120</span>        this.writer.writeNext(values);<a name="line.120"></a>
<span class="sourceLineNo">121</span>    }<a name="line.121"></a>
<span class="sourceLineNo">122</span><a name="line.122"></a>
<span class="sourceLineNo">123</span>    /**<a name="line.123"></a>
<span class="sourceLineNo">124</span>     * Flush output.<a name="line.124"></a>
<span class="sourceLineNo">125</span>     */<a name="line.125"></a>
<span class="sourceLineNo">126</span>    public void flush() throws IOException {<a name="line.126"></a>
<span class="sourceLineNo">127</span>        this.writer.flush();<a name="line.127"></a>
<span class="sourceLineNo">128</span>    }<a name="line.128"></a>
<span class="sourceLineNo">129</span><a name="line.129"></a>
<span class="sourceLineNo">130</span>    /**<a name="line.130"></a>
<span class="sourceLineNo">131</span>     * Close this instance and the underlying output.<a name="line.131"></a>
<span class="sourceLineNo">132</span>     */<a name="line.132"></a>
<span class="sourceLineNo">133</span>    public void close() throws IOException {<a name="line.133"></a>
<span class="sourceLineNo">134</span>        this.writer.close();<a name="line.134"></a>
<span class="sourceLineNo">135</span>    }<a name="line.135"></a>
<span class="sourceLineNo">136</span><a name="line.136"></a>
<span class="sourceLineNo">137</span>    /**<a name="line.137"></a>
<span class="sourceLineNo">138</span>     * Format a CSV column value.<a name="line.138"></a>
<span class="sourceLineNo">139</span>     *<a name="line.139"></a>
<span class="sourceLineNo">140</span>     * &lt;p&gt;<a name="line.140"></a>
<span class="sourceLineNo">141</span>     * The implementation in {@link CSVOutput} applies the following logic:<a name="line.141"></a>
<span class="sourceLineNo">142</span>     * &lt;ul&gt;<a name="line.142"></a>
<span class="sourceLineNo">143</span>     * &lt;li&gt;{@code null} values are output as the empty string&lt;/li&gt;<a name="line.143"></a>
<span class="sourceLineNo">144</span>     * &lt;li&gt;{@link Boolean} values are output as {@code 1} or {@code 0}&lt;/li&gt;<a name="line.144"></a>
<span class="sourceLineNo">145</span>     * &lt;li&gt;{@link Date} values are output by delegating to {@link #formatDate formatDate()}&lt;/li&gt;<a name="line.145"></a>
<span class="sourceLineNo">146</span>     * &lt;li&gt;All other objects are output using {@link String#valueOf}&lt;/li&gt;<a name="line.146"></a>
<span class="sourceLineNo">147</span>     * &lt;/ul&gt;<a name="line.147"></a>
<span class="sourceLineNo">148</span>     * &lt;/p&gt;<a name="line.148"></a>
<span class="sourceLineNo">149</span>     *<a name="line.149"></a>
<span class="sourceLineNo">150</span>     * &lt;p&gt;<a name="line.150"></a>
<span class="sourceLineNo">151</span>     * Subclasses should override as needed.<a name="line.151"></a>
<span class="sourceLineNo">152</span>     * &lt;/p&gt;<a name="line.152"></a>
<span class="sourceLineNo">153</span>     *<a name="line.153"></a>
<span class="sourceLineNo">154</span>     * @param columnName name of the column<a name="line.154"></a>
<span class="sourceLineNo">155</span>     * @param value column value; will be null if no value was present in the {@link Map} parameter to {@link #writeRow}<a name="line.155"></a>
<span class="sourceLineNo">156</span>     */<a name="line.156"></a>
<span class="sourceLineNo">157</span>    protected String formatObject(String columnName, Object value) {<a name="line.157"></a>
<span class="sourceLineNo">158</span>        if (value == null)<a name="line.158"></a>
<span class="sourceLineNo">159</span>            return "";<a name="line.159"></a>
<span class="sourceLineNo">160</span>        if (value instanceof Boolean)<a name="line.160"></a>
<span class="sourceLineNo">161</span>            return ((Boolean)value).booleanValue() ? "1" : "0";<a name="line.161"></a>
<span class="sourceLineNo">162</span>        if (value instanceof Date)<a name="line.162"></a>
<span class="sourceLineNo">163</span>            return this.formatDate(columnName, (Date)value);<a name="line.163"></a>
<span class="sourceLineNo">164</span>        return String.valueOf(value);<a name="line.164"></a>
<span class="sourceLineNo">165</span>    }<a name="line.165"></a>
<span class="sourceLineNo">166</span><a name="line.166"></a>
<span class="sourceLineNo">167</span>    /**<a name="line.167"></a>
<span class="sourceLineNo">168</span>     * Format a {@link Date} value.<a name="line.168"></a>
<span class="sourceLineNo">169</span>     *<a name="line.169"></a>
<span class="sourceLineNo">170</span>     * &lt;p&gt;<a name="line.170"></a>
<span class="sourceLineNo">171</span>     * The implementation in {@link CSVOutput} delegates to {@link DateEncoder#encode DateEncoder.encode()}.<a name="line.171"></a>
<span class="sourceLineNo">172</span>     * &lt;/p&gt;<a name="line.172"></a>
<span class="sourceLineNo">173</span>     *<a name="line.173"></a>
<span class="sourceLineNo">174</span>     * &lt;p&gt;<a name="line.174"></a>
<span class="sourceLineNo">175</span>     * Subclasses should override as needed.<a name="line.175"></a>
<span class="sourceLineNo">176</span>     * &lt;/p&gt;<a name="line.176"></a>
<span class="sourceLineNo">177</span>     *<a name="line.177"></a>
<span class="sourceLineNo">178</span>     * @param columnName name of the column<a name="line.178"></a>
<span class="sourceLineNo">179</span>     * @param date column value<a name="line.179"></a>
<span class="sourceLineNo">180</span>     * @throws IllegalArgumentException if {@code date} is null<a name="line.180"></a>
<span class="sourceLineNo">181</span>     */<a name="line.181"></a>
<span class="sourceLineNo">182</span>    protected String formatDate(String columnName, Date date) {<a name="line.182"></a>
<span class="sourceLineNo">183</span>        if (date == null)<a name="line.183"></a>
<span class="sourceLineNo">184</span>            throw new IllegalArgumentException("null date");<a name="line.184"></a>
<span class="sourceLineNo">185</span>        return DateEncoder.encode(date);<a name="line.185"></a>
<span class="sourceLineNo">186</span>    }<a name="line.186"></a>
<span class="sourceLineNo">187</span>}<a name="line.187"></a>
<span class="sourceLineNo">188</span><a name="line.188"></a>




























































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